terse variable names, simplify the plugin interface or consider tweaks
for maintainability.
* Renames plg -> plugin
* Renames mgr ->plugin_mgr (since in a combined window and composite
manager I think "mgr" will end up being ambiguous in places)
* Renames PluginWorkspaceRectangle -> MetaRectangle (We are no longer
concerned about mbwm2 portability)
* Renames a few one letter variable names e.g. a -> window, r ->rect
* Renames some vars to indicate what they represent not their data type,
e.g. group1, group2 ->workspace0, workspace1
* Renames the variable mcw -> mc_window to make it more immediately
obvious what it represents.
* Removes the verbose META_COMPOSITOR_CLUTTER_PLUGIN_SWITCH_WORKSPACE macro,
and just uses metacity_plugin instead.
* Instead of hanging data of the plugins global descriptor, we just use a
standalone static global variable.
* Make do_init a function pointer inside the plugin descriptors instead of
special casing it and using another g_module_symbol call. This also removes
the need for the META_COMPOSITOR_CLUTTER_PLUGIN_INIT_FUNC macro.
* A bunch of anal 80char fixes
* Removes the screen_width,height variables from the plugin descriptor struct
and add a plugin API instead.
